21st Century Tech Meets 15th Century Architecture

Can you imagine the Eiffel Tower with wind turbines? The Taj Mahal with rooftop solar panels? No matter how much you support renewable energy, it's jarring to think about retrofitting such famous and historic structures, but one Turkish architect suggests it can -- and should -- be done.Even if local law mandates energy efficiency for new construction, "existing building stock predominates," says architect Nilay Ozeler Kanan, who is affiliated with Osman Gazi University in Eskişehir and the Turkish Ministry of Public Works. "By renovating historic structures to eliminate energy needs, they can become used for performances, workshops, and other purposes."

Environmentalism vs. Preservationism?Many a homeowner has run into problems trying to upgrade poorly insulated windows, for example, on a historic home, a change that is often not allowed because it is thought to harm the historic character of the building. The topic is a subject of debate among environmentalists and preservationists in the United States. But the buildings Kanan is talking about aren't just 19th-century homes -- they're also 500-year-old palaces.

Such efforts have their downsides, the architect admitted in her talk at the 8th EcoCity World Summit last month in Istanbul, noting that there is a risk of damage to irreplaceable structures and that "each country must come up with its own standards and plans because historic buildings are unique."

But unlike in the recent past, she said, when "applying modern technology to historic buildings posed problems," new innovations such as building-integrated solar -- which is designed to blend in with a structure's roof or walls -- allow more design freedom while protecting aesthetic integrity. A coating of thin-film solar panels, for example, could be applied to the existing rooftop materials at Topkapı Sarayı, the Ottoman-era sultans' palace that is one of Istanbul's most famous landmarks.

Traditional black-basalt stone homes in Diyarbakır have some energy-efficient features. Photo by Jennifer Hattam.Integrating Modern Technology and Traditional Passive DesignModern techniques to maximize energy efficiency can also be integrated with the existing "passive design systems" of the buildings, which were often constructed in ways more suited to their climates than new homes and offices are. Black basalt was traditionally used to build homes in the southeast city of Diyarbakır, for example, where temperatures can top 40 degrees Celsius in the summer and drop way below 0 C in winter. Like other stone, it has high capacity for storing heat as well as a porous quality that aids in ventilation.

The famous yellow-limestone houses of Mardin, also in the country's southeast, have "high walls and half-exposed rooms to protect in hot climate," Kanan says, adding that their "south-facing terraces, courtyards, and front facades are well-suited to solar." The homes' hillside location and altitude would also allow them to generate wind. According to the architect, a 100-meter-square field of mono-crystalline solar cells would yield more than 26,000 kWh of energy.

Though "aesthetics is an issue," Kanan says, rooftop applications would disturb the historic character less. She also notes (correctly) that these buildings are "already marred by satellite dishes." So why not add a little solar to power that satellite?